Inferring the Breakdown Scales of the Chiral Expansions for g_A and m_N

Author(s)

• Andreas Ekström
• Daniel R. Phillips
• Lucas Platter
• Matthias Schindler, University of South CarolinaFollow

Document Type

Article

Abstract

We apply Bayesian inference to the order-by-order chiral perturbation theory (χPT) expansions for the axial-vector coupling constant g_A and the nucleon mass m_N, and thereby infer the scales at which χPT breaks down for these two observables. Using a pointwise Bayesian analysis, we find that the inferred breakdown scales are notably different for the two observables. For the chiral expansion of g_A, we obtain 251⁺²⁰₋₅₀ MeV and 211⁺²⁰₋₃₀ MeV using two distinct sets of low-energy constants, while for the chiral expansion of m_N we infer a significantly larger breakdown scale of 491⁺⁶⁰₋₉₀ MeV.

Digital Object Identifier (DOI)

https://doi.org/10.1016/j.physletb.2026.140352

Publication Info

Published in Physics Letters B, Volume 875, 2026.

© 2026 The Author(s). Published by Elsevier B.V. Funded by SCOAP³. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

APA Citation

Ekström, A., Phillips, D. R., Platter, L., & Schindler, M. R. (2026). Inferring the breakdown scales of the chiral expansions for g and m. Physics Letters B, 875, 140352.https://doi.org/10.1016/j.physletb.2026.140352